For driving heavy vehicles, such as trucks, buses and the like, vehicle economy has over time had an ever increasing impact on the profitability of the enterprise in which the vehicle is used. In addition to the cost of procurement of the vehicle, it is generally the case that the main items of expenditure for the running of a vehicle are the pay given to the driver of the vehicle, costs of repairs and maintenance, and fuel for propulsion of the vehicle.
Depending on the type of vehicle, different factors can have different levels of impact, but the fuel consumption is generally a substantial item of expenditure, and, since the degree of utilization of heavy vehicles is often high, associated with considerable total fuel consumption, the fuel costs can have a very great impact on profitability for an owner of the vehicle, for example a haulage company or the like.
Therefore, every possibility of reducing the fuel consumption can have a positive effect on profitability, and, especially in long-distance driving, it is especially important to optimize the fuel consumption. For example, for this purpose, long-distance vehicles are produced which are characterized by a typical cruising speed for the internal combustion engine, where the cruising speed is adapted for a certain operating speed. Typical operating speeds, depending on the region and/or type of road, can be, for example, 80 km/h, 85 km/h or 89 km/h.
In addition to fuel economy, it is becoming more and more important, in heavy vehicles, that the driver of the vehicle finds the driving experience comfortable and intuitive. For example, the use of automatically changing transmissions, where the change of gear is controlled completely or partially by the control system usually present in the vehicle, can make driving the vehicle easier.
Automatic gear change also permits further freedom in controlling the progress of the vehicle from the perspective of fuel economy, for example by using the control system of the vehicle to ensure that the vehicle is driven in a gear that is advantageous from the point of view of fuel economy.
However, good comfort for the driver also entails other aspects, for example ensuring good driveability, i.e. that the vehicle from a performance point of view, e.g. torque demand, responds in a manner expected by the driver, and also without undesired delay.